I'm trying to enlarge the interword spacing, because with ITC Kabel's default spacing it's sometimes hard to decide where is the space between two words. I read the manual of the microtype package, and I did some trying, without success. For example this one:

2 Answers
2

You can change the \fontdimen parameters controlling the interword spacing: \fontdimen2 (the normal interword space), \fontdimen3 (the amount of stretch of the interword space), and \fontdimen4 (the amount of shrink). A lttle example: